World Photos

People gather for a walk against warming march through in Sydney, Australia, Saturday, Dec. 12, 2009. The walk, which is also being held in other cities around the world, aims to send a message to the world leaders in Copenhagen and to raise the awareness of the general population to their task and in support for a binding climate change treaty in line with the scientific call for an urgent reduction of emissions to 350 parts per million CO2 in our atmosphere to avoid the tipping point to a runaway climate change. We are now at 387ppm.